1/* 2 * linux/include/linux/jbd2.h 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com> 5 * 6 * Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Definitions for transaction data structures for the buffer cache 13 * filesystem journaling support. 14 */ 15 16#ifndef _LINUX_JBD2_H 17#define _LINUX_JBD2_H 18 19/* Allow this file to be included directly into e2fsprogs */ 20#ifndef __KERNEL__ 21#include "jfs_compat.h" 22#define JBD2_DEBUG 23#else 24 25#include <linux/types.h> 26#include <linux/buffer_head.h> 27#include <linux/journal-head.h> 28#include <linux/stddef.h> 29#include <linux/mutex.h> 30#include <linux/timer.h> 31#include <linux/slab.h> 32#include <crypto/hash.h> 33#endif 34 35#define journal_oom_retry 1 36 37/* 38 * Define JBD2_PARANIOD_IOFAIL to cause a kernel BUG() if ext4 finds 39 * certain classes of error which can occur due to failed IOs. Under 40 * normal use we want ext4 to continue after such errors, because 41 * hardware _can_ fail, but for debugging purposes when running tests on 42 * known-good hardware we may want to trap these errors. 43 */ 44#undef JBD2_PARANOID_IOFAIL 45 46/* 47 * The default maximum commit age, in seconds. 48 */ 49#define JBD2_DEFAULT_MAX_COMMIT_AGE 5 50 51#ifdef CONFIG_JBD2_DEBUG 52/* 53 * Define JBD2_EXPENSIVE_CHECKING to enable more expensive internal 54 * consistency checks. By default we don't do this unless 55 * CONFIG_JBD2_DEBUG is on. 56 */ 57#define JBD2_EXPENSIVE_CHECKING 58extern ushort jbd2_journal_enable_debug; 59void __jbd2_debug(int level, const char *file, const char *func, 60 unsigned int line, const char *fmt, ...); 61 62#define jbd_debug(n, fmt, a...) \ 63 __jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a) 64#else 65#define jbd_debug(n, fmt, a...) /**/ 66#endif 67 68extern void *jbd2_alloc(size_t size, gfp_t flags); 69extern void jbd2_free(void *ptr, size_t size); 70 71#define JBD2_MIN_JOURNAL_BLOCKS 1024 72 73#ifdef __KERNEL__ 74 75/** 76 * typedef handle_t - The handle_t type represents a single atomic update being performed by some process. 77 * 78 * All filesystem modifications made by the process go 79 * through this handle. Recursive operations (such as quota operations) 80 * are gathered into a single update. 81 * 82 * The buffer credits field is used to account for journaled buffers 83 * being modified by the running process. To ensure that there is 84 * enough log space for all outstanding operations, we need to limit the 85 * number of outstanding buffers possible at any time. When the 86 * operation completes, any buffer credits not used are credited back to 87 * the transaction, so that at all times we know how many buffers the 88 * outstanding updates on a transaction might possibly touch. 89 * 90 * This is an opaque datatype. 91 **/ 92typedef struct jbd2_journal_handle handle_t; /* Atomic operation type */ 93 94 95/** 96 * typedef journal_t - The journal_t maintains all of the journaling state information for a single filesystem. 97 * 98 * journal_t is linked to from the fs superblock structure. 99 * 100 * We use the journal_t to keep track of all outstanding transaction 101 * activity on the filesystem, and to manage the state of the log 102 * writing process. 103 * 104 * This is an opaque datatype. 105 **/ 106typedef struct journal_s journal_t; /* Journal control structure */ 107#endif 108 109/* 110 * Internal structures used by the logging mechanism: 111 */ 112 113#define JBD2_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */ 114 115/* 116 * On-disk structures 117 */ 118 119/* 120 * Descriptor block types: 121 */ 122 123#define JBD2_DESCRIPTOR_BLOCK 1 124#define JBD2_COMMIT_BLOCK 2 125#define JBD2_SUPERBLOCK_V1 3 126#define JBD2_SUPERBLOCK_V2 4 127#define JBD2_REVOKE_BLOCK 5 128 129/* 130 * Standard header for all descriptor blocks: 131 */ 132typedef struct journal_header_s 133{ 134 __be32 h_magic; 135 __be32 h_blocktype; 136 __be32 h_sequence; 137} journal_header_t; 138 139/* 140 * Checksum types. 141 */ 142#define JBD2_CRC32_CHKSUM 1 143#define JBD2_MD5_CHKSUM 2 144#define JBD2_SHA1_CHKSUM 3 145#define JBD2_CRC32C_CHKSUM 4 146 147#define JBD2_CRC32_CHKSUM_SIZE 4 148 149#define JBD2_CHECKSUM_BYTES (32 / sizeof(u32)) 150/* 151 * Commit block header for storing transactional checksums: 152 * 153 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum* 154 * fields are used to store a checksum of the descriptor and data blocks. 155 * 156 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum 157 * field is used to store crc32c(uuid+commit_block). Each journal metadata 158 * block gets its own checksum, and data block checksums are stored in 159 * journal_block_tag (in the descriptor). The other h_chksum* fields are 160 * not used. 161 * 162 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses 163 * journal_block_tag3_t to store a full 32-bit checksum. Everything else 164 * is the same as v2. 165 * 166 * Checksum v1, v2, and v3 are mutually exclusive features. 167 */ 168struct commit_header { 169 __be32 h_magic; 170 __be32 h_blocktype; 171 __be32 h_sequence; 172 unsigned char h_chksum_type; 173 unsigned char h_chksum_size; 174 unsigned char h_padding[2]; 175 __be32 h_chksum[JBD2_CHECKSUM_BYTES]; 176 __be64 h_commit_sec; 177 __be32 h_commit_nsec; 178}; 179 180/* 181 * The block tag: used to describe a single buffer in the journal. 182 * t_blocknr_high is only used if INCOMPAT_64BIT is set, so this 183 * raw struct shouldn't be used for pointer math or sizeof() - use 184 * journal_tag_bytes(journal) instead to compute this. 185 */ 186typedef struct journal_block_tag3_s 187{ 188 __be32 t_blocknr; /* The on-disk block number */ 189 __be32 t_flags; /* See below */ 190 __be32 t_blocknr_high; /* most-significant high 32bits. */ 191 __be32 t_checksum; /* crc32c(uuid+seq+block) */ 192} journal_block_tag3_t; 193 194typedef struct journal_block_tag_s 195{ 196 __be32 t_blocknr; /* The on-disk block number */ 197 __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */ 198 __be16 t_flags; /* See below */ 199 __be32 t_blocknr_high; /* most-significant high 32bits. */ 200} journal_block_tag_t; 201 202/* Tail of descriptor block, for checksumming */ 203struct jbd2_journal_block_tail { 204 __be32 t_checksum; /* crc32c(uuid+descr_block) */ 205}; 206 207/* 208 * The revoke descriptor: used on disk to describe a series of blocks to 209 * be revoked from the log 210 */ 211typedef struct jbd2_journal_revoke_header_s 212{ 213 journal_header_t r_header; 214 __be32 r_count; /* Count of bytes used in the block */ 215} jbd2_journal_revoke_header_t; 216 217/* Tail of revoke block, for checksumming */ 218struct jbd2_journal_revoke_tail { 219 __be32 r_checksum; /* crc32c(uuid+revoke_block) */ 220}; 221 222/* Definitions for the journal tag flags word: */ 223#define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ 224#define JBD2_FLAG_SAME_UUID 2 /* block has same uuid as previous */ 225#define JBD2_FLAG_DELETED 4 /* block deleted by this transaction */ 226#define JBD2_FLAG_LAST_TAG 8 /* last tag in this descriptor block */ 227 228 229/* 230 * The journal superblock. All fields are in big-endian byte order. 231 */ 232typedef struct journal_superblock_s 233{ 234/* 0x0000 */ 235 journal_header_t s_header; 236 237/* 0x000C */ 238 /* Static information describing the journal */ 239 __be32 s_blocksize; /* journal device blocksize */ 240 __be32 s_maxlen; /* total blocks in journal file */ 241 __be32 s_first; /* first block of log information */ 242 243/* 0x0018 */ 244 /* Dynamic information describing the current state of the log */ 245 __be32 s_sequence; /* first commit ID expected in log */ 246 __be32 s_start; /* blocknr of start of log */ 247 248/* 0x0020 */ 249 /* Error value, as set by jbd2_journal_abort(). */ 250 __be32 s_errno; 251 252/* 0x0024 */ 253 /* Remaining fields are only valid in a version-2 superblock */ 254 __be32 s_feature_compat; /* compatible feature set */ 255 __be32 s_feature_incompat; /* incompatible feature set */ 256 __be32 s_feature_ro_compat; /* readonly-compatible feature set */ 257/* 0x0030 */ 258 __u8 s_uuid[16]; /* 128-bit uuid for journal */ 259 260/* 0x0040 */ 261 __be32 s_nr_users; /* Nr of filesystems sharing log */ 262 263 __be32 s_dynsuper; /* Blocknr of dynamic superblock copy*/ 264 265/* 0x0048 */ 266 __be32 s_max_transaction; /* Limit of journal blocks per trans.*/ 267 __be32 s_max_trans_data; /* Limit of data blocks per trans. */ 268 269/* 0x0050 */ 270 __u8 s_checksum_type; /* checksum type */ 271 __u8 s_padding2[3]; 272 __u32 s_padding[42]; 273 __be32 s_checksum; /* crc32c(superblock) */ 274 275/* 0x0100 */ 276 __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ 277/* 0x0400 */ 278} journal_superblock_t; 279 280#define JBD2_HAS_COMPAT_FEATURE(j,mask) \ 281 ((j)->j_format_version >= 2 && \ 282 ((j)->j_superblock->s_feature_compat & cpu_to_be32((mask)))) 283#define JBD2_HAS_RO_COMPAT_FEATURE(j,mask) \ 284 ((j)->j_format_version >= 2 && \ 285 ((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask)))) 286#define JBD2_HAS_INCOMPAT_FEATURE(j,mask) \ 287 ((j)->j_format_version >= 2 && \ 288 ((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask)))) 289 290#define JBD2_FEATURE_COMPAT_CHECKSUM 0x00000001 291 292#define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 293#define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 294#define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 295#define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008 296#define JBD2_FEATURE_INCOMPAT_CSUM_V3 0x00000010 297 298/* Features known to this kernel version: */ 299#define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM 300#define JBD2_KNOWN_ROCOMPAT_FEATURES 0 301#define JBD2_KNOWN_INCOMPAT_FEATURES (JBD2_FEATURE_INCOMPAT_REVOKE | \ 302 JBD2_FEATURE_INCOMPAT_64BIT | \ 303 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT | \ 304 JBD2_FEATURE_INCOMPAT_CSUM_V2 | \ 305 JBD2_FEATURE_INCOMPAT_CSUM_V3) 306 307#ifdef __KERNEL__ 308 309#include <linux/fs.h> 310#include <linux/sched.h> 311 312enum jbd_state_bits { 313 BH_JBD /* Has an attached ext3 journal_head */ 314 = BH_PrivateStart, 315 BH_JWrite, /* Being written to log (@@@ DEBUGGING) */ 316 BH_Freed, /* Has been freed (truncated) */ 317 BH_Revoked, /* Has been revoked from the log */ 318 BH_RevokeValid, /* Revoked flag is valid */ 319 BH_JBDDirty, /* Is dirty but journaled */ 320 BH_State, /* Pins most journal_head state */ 321 BH_JournalHead, /* Pins bh->b_private and jh->b_bh */ 322 BH_Shadow, /* IO on shadow buffer is running */ 323 BH_Verified, /* Metadata block has been verified ok */ 324 BH_JBDPrivateStart, /* First bit available for private use by FS */ 325}; 326 327BUFFER_FNS(JBD, jbd) 328BUFFER_FNS(JWrite, jwrite) 329BUFFER_FNS(JBDDirty, jbddirty) 330TAS_BUFFER_FNS(JBDDirty, jbddirty) 331BUFFER_FNS(Revoked, revoked) 332TAS_BUFFER_FNS(Revoked, revoked) 333BUFFER_FNS(RevokeValid, revokevalid) 334TAS_BUFFER_FNS(RevokeValid, revokevalid) 335BUFFER_FNS(Freed, freed) 336BUFFER_FNS(Shadow, shadow) 337BUFFER_FNS(Verified, verified) 338 339#include <linux/jbd_common.h> 340 341#define J_ASSERT(assert) BUG_ON(!(assert)) 342 343#define J_ASSERT_BH(bh, expr) J_ASSERT(expr) 344#define J_ASSERT_JH(jh, expr) J_ASSERT(expr) 345 346#if defined(JBD2_PARANOID_IOFAIL) 347#define J_EXPECT(expr, why...) J_ASSERT(expr) 348#define J_EXPECT_BH(bh, expr, why...) J_ASSERT_BH(bh, expr) 349#define J_EXPECT_JH(jh, expr, why...) J_ASSERT_JH(jh, expr) 350#else 351#define __journal_expect(expr, why...) \ 352 ({ \ 353 int val = (expr); \ 354 if (!val) { \ 355 printk(KERN_ERR \ 356 "JBD2 unexpected failure: %s: %s;\n", \ 357 __func__, #expr); \ 358 printk(KERN_ERR why "\n"); \ 359 } \ 360 val; \ 361 }) 362#define J_EXPECT(expr, why...) __journal_expect(expr, ## why) 363#define J_EXPECT_BH(bh, expr, why...) __journal_expect(expr, ## why) 364#define J_EXPECT_JH(jh, expr, why...) __journal_expect(expr, ## why) 365#endif 366 367/* Flags in jbd_inode->i_flags */ 368#define __JI_COMMIT_RUNNING 0 369/* Commit of the inode data in progress. We use this flag to protect us from 370 * concurrent deletion of inode. We cannot use reference to inode for this 371 * since we cannot afford doing last iput() on behalf of kjournald 372 */ 373#define JI_COMMIT_RUNNING (1 << __JI_COMMIT_RUNNING) 374 375/** 376 * struct jbd_inode is the structure linking inodes in ordered mode 377 * present in a transaction so that we can sync them during commit. 378 */ 379struct jbd2_inode { 380 /* Which transaction does this inode belong to? Either the running 381 * transaction or the committing one. [j_list_lock] */ 382 transaction_t *i_transaction; 383 384 /* Pointer to the running transaction modifying inode's data in case 385 * there is already a committing transaction touching it. [j_list_lock] */ 386 transaction_t *i_next_transaction; 387 388 /* List of inodes in the i_transaction [j_list_lock] */ 389 struct list_head i_list; 390 391 /* VFS inode this inode belongs to [constant during the lifetime 392 * of the structure] */ 393 struct inode *i_vfs_inode; 394 395 /* Flags of inode [j_list_lock] */ 396 unsigned long i_flags; 397}; 398 399struct jbd2_revoke_table_s; 400 401/** 402 * struct handle_s - The handle_s type is the concrete type associated with 403 * handle_t. 404 * @h_transaction: Which compound transaction is this update a part of? 405 * @h_buffer_credits: Number of remaining buffers we are allowed to dirty. 406 * @h_ref: Reference count on this handle 407 * @h_err: Field for caller's use to track errors through large fs operations 408 * @h_sync: flag for sync-on-close 409 * @h_jdata: flag to force data journaling 410 * @h_aborted: flag indicating fatal error on handle 411 **/ 412 413/* Docbook can't yet cope with the bit fields, but will leave the documentation 414 * in so it can be fixed later. 415 */ 416 417struct jbd2_journal_handle 418{ 419 union { 420 /* Which compound transaction is this update a part of? */ 421 transaction_t *h_transaction; 422 /* Which journal handle belongs to - used iff h_reserved set */ 423 journal_t *h_journal; 424 }; 425 426 /* Handle reserved for finishing the logical operation */ 427 handle_t *h_rsv_handle; 428 429 /* Number of remaining buffers we are allowed to dirty: */ 430 int h_buffer_credits; 431 432 /* Reference count on this handle */ 433 int h_ref; 434 435 /* Field for caller's use to track errors through large fs */ 436 /* operations */ 437 int h_err; 438 439 /* Flags [no locking] */ 440 unsigned int h_sync: 1; /* sync-on-close */ 441 unsigned int h_jdata: 1; /* force data journaling */ 442 unsigned int h_reserved: 1; /* handle with reserved credits */ 443 unsigned int h_aborted: 1; /* fatal error on handle */ 444 unsigned int h_type: 8; /* for handle statistics */ 445 unsigned int h_line_no: 16; /* for handle statistics */ 446 447 unsigned long h_start_jiffies; 448 unsigned int h_requested_credits; 449 450#ifdef CONFIG_DEBUG_LOCK_ALLOC 451 struct lockdep_map h_lockdep_map; 452#endif 453}; 454 455 456/* 457 * Some stats for checkpoint phase 458 */ 459struct transaction_chp_stats_s { 460 unsigned long cs_chp_time; 461 __u32 cs_forced_to_close; 462 __u32 cs_written; 463 __u32 cs_dropped; 464}; 465 466/* The transaction_t type is the guts of the journaling mechanism. It 467 * tracks a compound transaction through its various states: 468 * 469 * RUNNING: accepting new updates 470 * LOCKED: Updates still running but we don't accept new ones 471 * RUNDOWN: Updates are tidying up but have finished requesting 472 * new buffers to modify (state not used for now) 473 * FLUSH: All updates complete, but we are still writing to disk 474 * COMMIT: All data on disk, writing commit record 475 * FINISHED: We still have to keep the transaction for checkpointing. 476 * 477 * The transaction keeps track of all of the buffers modified by a 478 * running transaction, and all of the buffers committed but not yet 479 * flushed to home for finished transactions. 480 */ 481 482/* 483 * Lock ranking: 484 * 485 * j_list_lock 486 * ->jbd_lock_bh_journal_head() (This is "innermost") 487 * 488 * j_state_lock 489 * ->jbd_lock_bh_state() 490 * 491 * jbd_lock_bh_state() 492 * ->j_list_lock 493 * 494 * j_state_lock 495 * ->t_handle_lock 496 * 497 * j_state_lock 498 * ->j_list_lock (journal_unmap_buffer) 499 * 500 */ 501 502struct transaction_s 503{ 504 /* Pointer to the journal for this transaction. [no locking] */ 505 journal_t *t_journal; 506 507 /* Sequence number for this transaction [no locking] */ 508 tid_t t_tid; 509 510 /* 511 * Transaction's current state 512 * [no locking - only kjournald2 alters this] 513 * [j_list_lock] guards transition of a transaction into T_FINISHED 514 * state and subsequent call of __jbd2_journal_drop_transaction() 515 * FIXME: needs barriers 516 * KLUDGE: [use j_state_lock] 517 */ 518 enum { 519 T_RUNNING, 520 T_LOCKED, 521 T_FLUSH, 522 T_COMMIT, 523 T_COMMIT_DFLUSH, 524 T_COMMIT_JFLUSH, 525 T_COMMIT_CALLBACK, 526 T_FINISHED 527 } t_state; 528 529 /* 530 * Where in the log does this transaction's commit start? [no locking] 531 */ 532 unsigned long t_log_start; 533 534 /* Number of buffers on the t_buffers list [j_list_lock] */ 535 int t_nr_buffers; 536 537 /* 538 * Doubly-linked circular list of all buffers reserved but not yet 539 * modified by this transaction [j_list_lock] 540 */ 541 struct journal_head *t_reserved_list; 542 543 /* 544 * Doubly-linked circular list of all metadata buffers owned by this 545 * transaction [j_list_lock] 546 */ 547 struct journal_head *t_buffers; 548 549 /* 550 * Doubly-linked circular list of all forget buffers (superseded 551 * buffers which we can un-checkpoint once this transaction commits) 552 * [j_list_lock] 553 */ 554 struct journal_head *t_forget; 555 556 /* 557 * Doubly-linked circular list of all buffers still to be flushed before 558 * this transaction can be checkpointed. [j_list_lock] 559 */ 560 struct journal_head *t_checkpoint_list; 561 562 /* 563 * Doubly-linked circular list of all buffers submitted for IO while 564 * checkpointing. [j_list_lock] 565 */ 566 struct journal_head *t_checkpoint_io_list; 567 568 /* 569 * Doubly-linked circular list of metadata buffers being shadowed by log 570 * IO. The IO buffers on the iobuf list and the shadow buffers on this 571 * list match each other one for one at all times. [j_list_lock] 572 */ 573 struct journal_head *t_shadow_list; 574 575 /* 576 * List of inodes whose data we've modified in data=ordered mode. 577 * [j_list_lock] 578 */ 579 struct list_head t_inode_list; 580 581 /* 582 * Protects info related to handles 583 */ 584 spinlock_t t_handle_lock; 585 586 /* 587 * Longest time some handle had to wait for running transaction 588 */ 589 unsigned long t_max_wait; 590 591 /* 592 * When transaction started 593 */ 594 unsigned long t_start; 595 596 /* 597 * When commit was requested 598 */ 599 unsigned long t_requested; 600 601 /* 602 * Checkpointing stats [j_checkpoint_sem] 603 */ 604 struct transaction_chp_stats_s t_chp_stats; 605 606 /* 607 * Number of outstanding updates running on this transaction 608 * [t_handle_lock] 609 */ 610 atomic_t t_updates; 611 612 /* 613 * Number of buffers reserved for use by all handles in this transaction 614 * handle but not yet modified. [t_handle_lock] 615 */ 616 atomic_t t_outstanding_credits; 617 618 /* 619 * Forward and backward links for the circular list of all transactions 620 * awaiting checkpoint. [j_list_lock] 621 */ 622 transaction_t *t_cpnext, *t_cpprev; 623 624 /* 625 * When will the transaction expire (become due for commit), in jiffies? 626 * [no locking] 627 */ 628 unsigned long t_expires; 629 630 /* 631 * When this transaction started, in nanoseconds [no locking] 632 */ 633 ktime_t t_start_time; 634 635 /* 636 * How many handles used this transaction? [t_handle_lock] 637 */ 638 atomic_t t_handle_count; 639 640 /* 641 * This transaction is being forced and some process is 642 * waiting for it to finish. 643 */ 644 unsigned int t_synchronous_commit:1; 645 646 /* Disk flush needs to be sent to fs partition [no locking] */ 647 int t_need_data_flush; 648 649 /* 650 * For use by the filesystem to store fs-specific data 651 * structures associated with the transaction 652 */ 653 struct list_head t_private_list; 654}; 655 656struct transaction_run_stats_s { 657 unsigned long rs_wait; 658 unsigned long rs_request_delay; 659 unsigned long rs_running; 660 unsigned long rs_locked; 661 unsigned long rs_flushing; 662 unsigned long rs_logging; 663 664 __u32 rs_handle_count; 665 __u32 rs_blocks; 666 __u32 rs_blocks_logged; 667}; 668 669struct transaction_stats_s { 670 unsigned long ts_tid; 671 unsigned long ts_requested; 672 struct transaction_run_stats_s run; 673}; 674 675static inline unsigned long 676jbd2_time_diff(unsigned long start, unsigned long end) 677{ 678 if (end >= start) 679 return end - start; 680 681 return end + (MAX_JIFFY_OFFSET - start); 682} 683 684#define JBD2_NR_BATCH 64 685 686/** 687 * struct journal_s - The journal_s type is the concrete type associated with 688 * journal_t. 689 * @j_flags: General journaling state flags 690 * @j_errno: Is there an outstanding uncleared error on the journal (from a 691 * prior abort)? 692 * @j_sb_buffer: First part of superblock buffer 693 * @j_superblock: Second part of superblock buffer 694 * @j_format_version: Version of the superblock format 695 * @j_state_lock: Protect the various scalars in the journal 696 * @j_barrier_count: Number of processes waiting to create a barrier lock 697 * @j_barrier: The barrier lock itself 698 * @j_running_transaction: The current running transaction.. 699 * @j_committing_transaction: the transaction we are pushing to disk 700 * @j_checkpoint_transactions: a linked circular list of all transactions 701 * waiting for checkpointing 702 * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction 703 * to start committing, or for a barrier lock to be released 704 * @j_wait_done_commit: Wait queue for waiting for commit to complete 705 * @j_wait_commit: Wait queue to trigger commit 706 * @j_wait_updates: Wait queue to wait for updates to complete 707 * @j_wait_reserved: Wait queue to wait for reserved buffer credits to drop 708 * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints 709 * @j_head: Journal head - identifies the first unused block in the journal 710 * @j_tail: Journal tail - identifies the oldest still-used block in the 711 * journal. 712 * @j_free: Journal free - how many free blocks are there in the journal? 713 * @j_first: The block number of the first usable block 714 * @j_last: The block number one beyond the last usable block 715 * @j_dev: Device where we store the journal 716 * @j_blocksize: blocksize for the location where we store the journal. 717 * @j_blk_offset: starting block offset for into the device where we store the 718 * journal 719 * @j_fs_dev: Device which holds the client fs. For internal journal this will 720 * be equal to j_dev 721 * @j_reserved_credits: Number of buffers reserved from the running transaction 722 * @j_maxlen: Total maximum capacity of the journal region on disk. 723 * @j_list_lock: Protects the buffer lists and internal buffer state. 724 * @j_inode: Optional inode where we store the journal. If present, all journal 725 * block numbers are mapped into this inode via bmap(). 726 * @j_tail_sequence: Sequence number of the oldest transaction in the log 727 * @j_transaction_sequence: Sequence number of the next transaction to grant 728 * @j_commit_sequence: Sequence number of the most recently committed 729 * transaction 730 * @j_commit_request: Sequence number of the most recent transaction wanting 731 * commit 732 * @j_uuid: Uuid of client object. 733 * @j_task: Pointer to the current commit thread for this journal 734 * @j_max_transaction_buffers: Maximum number of metadata buffers to allow in a 735 * single compound commit transaction 736 * @j_commit_interval: What is the maximum transaction lifetime before we begin 737 * a commit? 738 * @j_commit_timer: The timer used to wakeup the commit thread 739 * @j_revoke_lock: Protect the revoke table 740 * @j_revoke: The revoke table - maintains the list of revoked blocks in the 741 * current transaction. 742 * @j_revoke_table: alternate revoke tables for j_revoke 743 * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction 744 * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the 745 * number that will fit in j_blocksize 746 * @j_last_sync_writer: most recent pid which did a synchronous write 747 * @j_history: Buffer storing the transactions statistics history 748 * @j_history_max: Maximum number of transactions in the statistics history 749 * @j_history_cur: Current number of transactions in the statistics history 750 * @j_history_lock: Protect the transactions statistics history 751 * @j_proc_entry: procfs entry for the jbd statistics directory 752 * @j_stats: Overall statistics 753 * @j_private: An opaque pointer to fs-private information. 754 */ 755 756struct journal_s 757{ 758 /* General journaling state flags [j_state_lock] */ 759 unsigned long j_flags; 760 761 /* 762 * Is there an outstanding uncleared error on the journal (from a prior 763 * abort)? [j_state_lock] 764 */ 765 int j_errno; 766 767 /* The superblock buffer */ 768 struct buffer_head *j_sb_buffer; 769 journal_superblock_t *j_superblock; 770 771 /* Version of the superblock format */ 772 int j_format_version; 773 774 /* 775 * Protect the various scalars in the journal 776 */ 777 rwlock_t j_state_lock; 778 779 /* 780 * Number of processes waiting to create a barrier lock [j_state_lock] 781 */ 782 int j_barrier_count; 783 784 /* The barrier lock itself */ 785 struct mutex j_barrier; 786 787 /* 788 * Transactions: The current running transaction... 789 * [j_state_lock] [caller holding open handle] 790 */ 791 transaction_t *j_running_transaction; 792 793 /* 794 * the transaction we are pushing to disk 795 * [j_state_lock] [caller holding open handle] 796 */ 797 transaction_t *j_committing_transaction; 798 799 /* 800 * ... and a linked circular list of all transactions waiting for 801 * checkpointing. [j_list_lock] 802 */ 803 transaction_t *j_checkpoint_transactions; 804 805 /* 806 * Wait queue for waiting for a locked transaction to start committing, 807 * or for a barrier lock to be released 808 */ 809 wait_queue_head_t j_wait_transaction_locked; 810 811 /* Wait queue for waiting for commit to complete */ 812 wait_queue_head_t j_wait_done_commit; 813 814 /* Wait queue to trigger commit */ 815 wait_queue_head_t j_wait_commit; 816 817 /* Wait queue to wait for updates to complete */ 818 wait_queue_head_t j_wait_updates; 819 820 /* Wait queue to wait for reserved buffer credits to drop */ 821 wait_queue_head_t j_wait_reserved; 822 823 /* Semaphore for locking against concurrent checkpoints */ 824 struct mutex j_checkpoint_mutex; 825 826 /* 827 * List of buffer heads used by the checkpoint routine. This 828 * was moved from jbd2_log_do_checkpoint() to reduce stack 829 * usage. Access to this array is controlled by the 830 * j_checkpoint_mutex. [j_checkpoint_mutex] 831 */ 832 struct buffer_head *j_chkpt_bhs[JBD2_NR_BATCH]; 833 834 /* 835 * Journal head: identifies the first unused block in the journal. 836 * [j_state_lock] 837 */ 838 unsigned long j_head; 839 840 /* 841 * Journal tail: identifies the oldest still-used block in the journal. 842 * [j_state_lock] 843 */ 844 unsigned long j_tail; 845 846 /* 847 * Journal free: how many free blocks are there in the journal? 848 * [j_state_lock] 849 */ 850 unsigned long j_free; 851 852 /* 853 * Journal start and end: the block numbers of the first usable block 854 * and one beyond the last usable block in the journal. [j_state_lock] 855 */ 856 unsigned long j_first; 857 unsigned long j_last; 858 859 /* 860 * Device, blocksize and starting block offset for the location where we 861 * store the journal. 862 */ 863 struct block_device *j_dev; 864 int j_blocksize; 865 unsigned long long j_blk_offset; 866 char j_devname[BDEVNAME_SIZE+24]; 867 868 /* 869 * Device which holds the client fs. For internal journal this will be 870 * equal to j_dev. 871 */ 872 struct block_device *j_fs_dev; 873 874 /* Total maximum capacity of the journal region on disk. */ 875 unsigned int j_maxlen; 876 877 /* Number of buffers reserved from the running transaction */ 878 atomic_t j_reserved_credits; 879 880 /* 881 * Protects the buffer lists and internal buffer state. 882 */ 883 spinlock_t j_list_lock; 884 885 /* Optional inode where we store the journal. If present, all */ 886 /* journal block numbers are mapped into this inode via */ 887 /* bmap(). */ 888 struct inode *j_inode; 889 890 /* 891 * Sequence number of the oldest transaction in the log [j_state_lock] 892 */ 893 tid_t j_tail_sequence; 894 895 /* 896 * Sequence number of the next transaction to grant [j_state_lock] 897 */ 898 tid_t j_transaction_sequence; 899 900 /* 901 * Sequence number of the most recently committed transaction 902 * [j_state_lock]. 903 */ 904 tid_t j_commit_sequence; 905 906 /* 907 * Sequence number of the most recent transaction wanting commit 908 * [j_state_lock] 909 */ 910 tid_t j_commit_request; 911 912 /* 913 * Journal uuid: identifies the object (filesystem, LVM volume etc) 914 * backed by this journal. This will eventually be replaced by an array 915 * of uuids, allowing us to index multiple devices within a single 916 * journal and to perform atomic updates across them. 917 */ 918 __u8 j_uuid[16]; 919 920 /* Pointer to the current commit thread for this journal */ 921 struct task_struct *j_task; 922 923 /* 924 * Maximum number of metadata buffers to allow in a single compound 925 * commit transaction 926 */ 927 int j_max_transaction_buffers; 928 929 /* 930 * What is the maximum transaction lifetime before we begin a commit? 931 */ 932 unsigned long j_commit_interval; 933 934 /* The timer used to wakeup the commit thread: */ 935 struct timer_list j_commit_timer; 936 937 /* 938 * The revoke table: maintains the list of revoked blocks in the 939 * current transaction. [j_revoke_lock] 940 */ 941 spinlock_t j_revoke_lock; 942 struct jbd2_revoke_table_s *j_revoke; 943 struct jbd2_revoke_table_s *j_revoke_table[2]; 944 945 /* 946 * array of bhs for jbd2_journal_commit_transaction 947 */ 948 struct buffer_head **j_wbuf; 949 int j_wbufsize; 950 951 /* 952 * this is the pid of hte last person to run a synchronous operation 953 * through the journal 954 */ 955 pid_t j_last_sync_writer; 956 957 /* 958 * the average amount of time in nanoseconds it takes to commit a 959 * transaction to disk. [j_state_lock] 960 */ 961 u64 j_average_commit_time; 962 963 /* 964 * minimum and maximum times that we should wait for 965 * additional filesystem operations to get batched into a 966 * synchronous handle in microseconds 967 */ 968 u32 j_min_batch_time; 969 u32 j_max_batch_time; 970 971 /* This function is called when a transaction is closed */ 972 void (*j_commit_callback)(journal_t *, 973 transaction_t *); 974 975 /* 976 * Journal statistics 977 */ 978 spinlock_t j_history_lock; 979 struct proc_dir_entry *j_proc_entry; 980 struct transaction_stats_s j_stats; 981 982 /* Failed journal commit ID */ 983 unsigned int j_failed_commit; 984 985 /* 986 * An opaque pointer to fs-private information. ext3 puts its 987 * superblock pointer here 988 */ 989 void *j_private; 990 991 /* Reference to checksum algorithm driver via cryptoapi */ 992 struct crypto_shash *j_chksum_driver; 993 994 /* Precomputed journal UUID checksum for seeding other checksums */ 995 __u32 j_csum_seed; 996}; 997 998/* 999 * Journal flag definitions 1000 */ 1001#define JBD2_UNMOUNT 0x001 /* Journal thread is being destroyed */ 1002#define JBD2_ABORT 0x002 /* Journaling has been aborted for errors. */ 1003#define JBD2_ACK_ERR 0x004 /* The errno in the sb has been acked */ 1004#define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */ 1005#define JBD2_LOADED 0x010 /* The journal superblock has been loaded */ 1006#define JBD2_BARRIER 0x020 /* Use IDE barriers */ 1007#define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file 1008 * data write error in ordered 1009 * mode */ 1010#define JBD2_REC_ERR 0x080 /* The errno in the sb has been recorded */ 1011 1012/* 1013 * Function declarations for the journaling transaction and buffer 1014 * management 1015 */ 1016 1017/* Filing buffers */ 1018extern void jbd2_journal_unfile_buffer(journal_t *, struct journal_head *); 1019extern void __jbd2_journal_refile_buffer(struct journal_head *); 1020extern void jbd2_journal_refile_buffer(journal_t *, struct journal_head *); 1021extern void __jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1022extern void __journal_free_buffer(struct journal_head *bh); 1023extern void jbd2_journal_file_buffer(struct journal_head *, transaction_t *, int); 1024extern void __journal_clean_data_list(transaction_t *transaction); 1025static inline void jbd2_file_log_bh(struct list_head *head, struct buffer_head *bh) 1026{ 1027 list_add_tail(&bh->b_assoc_buffers, head); 1028} 1029static inline void jbd2_unfile_log_bh(struct buffer_head *bh) 1030{ 1031 list_del_init(&bh->b_assoc_buffers); 1032} 1033 1034/* Log buffer allocation */ 1035struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal); 1036int jbd2_journal_next_log_block(journal_t *, unsigned long long *); 1037int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 1038 unsigned long *block); 1039int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1040void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block); 1041 1042/* Commit management */ 1043extern void jbd2_journal_commit_transaction(journal_t *); 1044 1045/* Checkpoint list management */ 1046void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy); 1047int __jbd2_journal_remove_checkpoint(struct journal_head *); 1048void jbd2_journal_destroy_checkpoint(journal_t *journal); 1049void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *); 1050 1051 1052/* 1053 * Triggers 1054 */ 1055 1056struct jbd2_buffer_trigger_type { 1057 /* 1058 * Fired a the moment data to write to the journal are known to be 1059 * stable - so either at the moment b_frozen_data is created or just 1060 * before a buffer is written to the journal. mapped_data is a mapped 1061 * buffer that is the frozen data for commit. 1062 */ 1063 void (*t_frozen)(struct jbd2_buffer_trigger_type *type, 1064 struct buffer_head *bh, void *mapped_data, 1065 size_t size); 1066 1067 /* 1068 * Fired during journal abort for dirty buffers that will not be 1069 * committed. 1070 */ 1071 void (*t_abort)(struct jbd2_buffer_trigger_type *type, 1072 struct buffer_head *bh); 1073}; 1074 1075extern void jbd2_buffer_frozen_trigger(struct journal_head *jh, 1076 void *mapped_data, 1077 struct jbd2_buffer_trigger_type *triggers); 1078extern void jbd2_buffer_abort_trigger(struct journal_head *jh, 1079 struct jbd2_buffer_trigger_type *triggers); 1080 1081/* Buffer IO */ 1082extern int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 1083 struct journal_head *jh_in, 1084 struct buffer_head **bh_out, 1085 sector_t blocknr); 1086 1087/* Transaction locking */ 1088extern void __wait_on_journal (journal_t *); 1089 1090/* Transaction cache support */ 1091extern void jbd2_journal_destroy_transaction_cache(void); 1092extern int jbd2_journal_init_transaction_cache(void); 1093extern void jbd2_journal_free_transaction(transaction_t *); 1094 1095/* 1096 * Journal locking. 1097 * 1098 * We need to lock the journal during transaction state changes so that nobody 1099 * ever tries to take a handle on the running transaction while we are in the 1100 * middle of moving it to the commit phase. j_state_lock does this. 1101 * 1102 * Note that the locking is completely interrupt unsafe. We never touch 1103 * journal structures from interrupts. 1104 */ 1105 1106static inline handle_t *journal_current_handle(void) 1107{ 1108 return current->journal_info; 1109} 1110 1111/* The journaling code user interface: 1112 * 1113 * Create and destroy handles 1114 * Register buffer modifications against the current transaction. 1115 */ 1116 1117extern handle_t *jbd2_journal_start(journal_t *, int nblocks); 1118extern handle_t *jbd2__journal_start(journal_t *, int blocks, int rsv_blocks, 1119 gfp_t gfp_mask, unsigned int type, 1120 unsigned int line_no); 1121extern int jbd2_journal_restart(handle_t *, int nblocks); 1122extern int jbd2__journal_restart(handle_t *, int nblocks, gfp_t gfp_mask); 1123extern int jbd2_journal_start_reserved(handle_t *handle, 1124 unsigned int type, unsigned int line_no); 1125extern void jbd2_journal_free_reserved(handle_t *handle); 1126extern int jbd2_journal_extend (handle_t *, int nblocks); 1127extern int jbd2_journal_get_write_access(handle_t *, struct buffer_head *); 1128extern int jbd2_journal_get_create_access (handle_t *, struct buffer_head *); 1129extern int jbd2_journal_get_undo_access(handle_t *, struct buffer_head *); 1130void jbd2_journal_set_triggers(struct buffer_head *, 1131 struct jbd2_buffer_trigger_type *type); 1132extern int jbd2_journal_dirty_metadata (handle_t *, struct buffer_head *); 1133extern int jbd2_journal_forget (handle_t *, struct buffer_head *); 1134extern void journal_sync_buffer (struct buffer_head *); 1135extern int jbd2_journal_invalidatepage(journal_t *, 1136 struct page *, unsigned int, unsigned int); 1137extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); 1138extern int jbd2_journal_stop(handle_t *); 1139extern int jbd2_journal_flush (journal_t *); 1140extern void jbd2_journal_lock_updates (journal_t *); 1141extern void jbd2_journal_unlock_updates (journal_t *); 1142 1143extern journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1144 struct block_device *fs_dev, 1145 unsigned long long start, int len, int bsize); 1146extern journal_t * jbd2_journal_init_inode (struct inode *); 1147extern int jbd2_journal_update_format (journal_t *); 1148extern int jbd2_journal_check_used_features 1149 (journal_t *, unsigned long, unsigned long, unsigned long); 1150extern int jbd2_journal_check_available_features 1151 (journal_t *, unsigned long, unsigned long, unsigned long); 1152extern int jbd2_journal_set_features 1153 (journal_t *, unsigned long, unsigned long, unsigned long); 1154extern void jbd2_journal_clear_features 1155 (journal_t *, unsigned long, unsigned long, unsigned long); 1156extern int jbd2_journal_load (journal_t *journal); 1157extern int jbd2_journal_destroy (journal_t *); 1158extern int jbd2_journal_recover (journal_t *journal); 1159extern int jbd2_journal_wipe (journal_t *, int); 1160extern int jbd2_journal_skip_recovery (journal_t *); 1161extern void jbd2_journal_update_sb_errno(journal_t *); 1162extern int jbd2_journal_update_sb_log_tail (journal_t *, tid_t, 1163 unsigned long, int); 1164extern void __jbd2_journal_abort_hard (journal_t *); 1165extern void jbd2_journal_abort (journal_t *, int); 1166extern int jbd2_journal_errno (journal_t *); 1167extern void jbd2_journal_ack_err (journal_t *); 1168extern int jbd2_journal_clear_err (journal_t *); 1169extern int jbd2_journal_bmap(journal_t *, unsigned long, unsigned long long *); 1170extern int jbd2_journal_force_commit(journal_t *); 1171extern int jbd2_journal_force_commit_nested(journal_t *); 1172extern int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *inode); 1173extern int jbd2_journal_begin_ordered_truncate(journal_t *journal, 1174 struct jbd2_inode *inode, loff_t new_size); 1175extern void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode); 1176extern void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode); 1177 1178/* 1179 * journal_head management 1180 */ 1181struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh); 1182struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh); 1183void jbd2_journal_put_journal_head(struct journal_head *jh); 1184 1185/* 1186 * handle management 1187 */ 1188extern struct kmem_cache *jbd2_handle_cache; 1189 1190static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags) 1191{ 1192 return kmem_cache_zalloc(jbd2_handle_cache, gfp_flags); 1193} 1194 1195static inline void jbd2_free_handle(handle_t *handle) 1196{ 1197 kmem_cache_free(jbd2_handle_cache, handle); 1198} 1199 1200/* 1201 * jbd2_inode management (optional, for those file systems that want to use 1202 * dynamically allocated jbd2_inode structures) 1203 */ 1204extern struct kmem_cache *jbd2_inode_cache; 1205 1206static inline struct jbd2_inode *jbd2_alloc_inode(gfp_t gfp_flags) 1207{ 1208 return kmem_cache_alloc(jbd2_inode_cache, gfp_flags); 1209} 1210 1211static inline void jbd2_free_inode(struct jbd2_inode *jinode) 1212{ 1213 kmem_cache_free(jbd2_inode_cache, jinode); 1214} 1215 1216/* Primary revoke support */ 1217#define JOURNAL_REVOKE_DEFAULT_HASH 256 1218extern int jbd2_journal_init_revoke(journal_t *, int); 1219extern void jbd2_journal_destroy_revoke_caches(void); 1220extern int jbd2_journal_init_revoke_caches(void); 1221 1222extern void jbd2_journal_destroy_revoke(journal_t *); 1223extern int jbd2_journal_revoke (handle_t *, unsigned long long, struct buffer_head *); 1224extern int jbd2_journal_cancel_revoke(handle_t *, struct journal_head *); 1225extern void jbd2_journal_write_revoke_records(journal_t *journal, 1226 transaction_t *transaction, 1227 struct list_head *log_bufs, 1228 int write_op); 1229 1230/* Recovery revoke support */ 1231extern int jbd2_journal_set_revoke(journal_t *, unsigned long long, tid_t); 1232extern int jbd2_journal_test_revoke(journal_t *, unsigned long long, tid_t); 1233extern void jbd2_journal_clear_revoke(journal_t *); 1234extern void jbd2_journal_switch_revoke_table(journal_t *journal); 1235extern void jbd2_clear_buffer_revoked_flags(journal_t *journal); 1236 1237/* 1238 * The log thread user interface: 1239 * 1240 * Request space in the current transaction, and force transaction commit 1241 * transitions on demand. 1242 */ 1243 1244int jbd2_log_start_commit(journal_t *journal, tid_t tid); 1245int __jbd2_log_start_commit(journal_t *journal, tid_t tid); 1246int jbd2_journal_start_commit(journal_t *journal, tid_t *tid); 1247int jbd2_log_wait_commit(journal_t *journal, tid_t tid); 1248int jbd2_complete_transaction(journal_t *journal, tid_t tid); 1249int jbd2_log_do_checkpoint(journal_t *journal); 1250int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid); 1251 1252void __jbd2_log_wait_for_space(journal_t *journal); 1253extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *); 1254extern int jbd2_cleanup_journal_tail(journal_t *); 1255 1256/* 1257 * is_journal_abort 1258 * 1259 * Simple test wrapper function to test the JBD2_ABORT state flag. This 1260 * bit, when set, indicates that we have had a fatal error somewhere, 1261 * either inside the journaling layer or indicated to us by the client 1262 * (eg. ext3), and that we and should not commit any further 1263 * transactions. 1264 */ 1265 1266static inline int is_journal_aborted(journal_t *journal) 1267{ 1268 return journal->j_flags & JBD2_ABORT; 1269} 1270 1271static inline int is_handle_aborted(handle_t *handle) 1272{ 1273 if (handle->h_aborted || !handle->h_transaction) 1274 return 1; 1275 return is_journal_aborted(handle->h_transaction->t_journal); 1276} 1277 1278static inline void jbd2_journal_abort_handle(handle_t *handle) 1279{ 1280 handle->h_aborted = 1; 1281} 1282 1283#endif /* __KERNEL__ */ 1284 1285/* Comparison functions for transaction IDs: perform comparisons using 1286 * modulo arithmetic so that they work over sequence number wraps. */ 1287 1288static inline int tid_gt(tid_t x, tid_t y) 1289{ 1290 int difference = (x - y); 1291 return (difference > 0); 1292} 1293 1294static inline int tid_geq(tid_t x, tid_t y) 1295{ 1296 int difference = (x - y); 1297 return (difference >= 0); 1298} 1299 1300extern int jbd2_journal_blocks_per_page(struct inode *inode); 1301extern size_t journal_tag_bytes(journal_t *journal); 1302 1303static inline int jbd2_journal_has_csum_v2or3(journal_t *journal) 1304{ 1305 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) || 1306 JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3)) 1307 return 1; 1308 1309 return 0; 1310} 1311 1312/* 1313 * We reserve t_outstanding_credits >> JBD2_CONTROL_BLOCKS_SHIFT for 1314 * transaction control blocks. 1315 */ 1316#define JBD2_CONTROL_BLOCKS_SHIFT 5 1317 1318/* 1319 * Return the minimum number of blocks which must be free in the journal 1320 * before a new transaction may be started. Must be called under j_state_lock. 1321 */ 1322static inline int jbd2_space_needed(journal_t *journal) 1323{ 1324 int nblocks = journal->j_max_transaction_buffers; 1325 return nblocks + (nblocks >> JBD2_CONTROL_BLOCKS_SHIFT); 1326} 1327 1328/* 1329 * Return number of free blocks in the log. Must be called under j_state_lock. 1330 */ 1331static inline unsigned long jbd2_log_space_left(journal_t *journal) 1332{ 1333 /* Allow for rounding errors */ 1334 unsigned long free = journal->j_free - 32; 1335 1336 if (journal->j_committing_transaction) { 1337 unsigned long committing = atomic_read(&journal-> 1338 j_committing_transaction->t_outstanding_credits); 1339 1340 /* Transaction + control blocks */ 1341 free -= committing + (committing >> JBD2_CONTROL_BLOCKS_SHIFT); 1342 } 1343 return free; 1344} 1345 1346/* 1347 * Definitions which augment the buffer_head layer 1348 */ 1349 1350/* journaling buffer types */ 1351#define BJ_None 0 /* Not journaled */ 1352#define BJ_Metadata 1 /* Normal journaled metadata */ 1353#define BJ_Forget 2 /* Buffer superseded by this transaction */ 1354#define BJ_Shadow 3 /* Buffer contents being shadowed to the log */ 1355#define BJ_Reserved 4 /* Buffer is reserved for access by journal */ 1356#define BJ_Types 5 1357 1358extern int jbd_blocks_per_page(struct inode *inode); 1359 1360/* JBD uses a CRC32 checksum */ 1361#define JBD_MAX_CHECKSUM_SIZE 4 1362 1363static inline u32 jbd2_chksum(journal_t *journal, u32 crc, 1364 const void *address, unsigned int length) 1365{ 1366 struct { 1367 struct shash_desc shash; 1368 char ctx[JBD_MAX_CHECKSUM_SIZE]; 1369 } desc; 1370 int err; 1371 1372 BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) > 1373 JBD_MAX_CHECKSUM_SIZE); 1374 1375 desc.shash.tfm = journal->j_chksum_driver; 1376 desc.shash.flags = 0; 1377 *(u32 *)desc.ctx = crc; 1378 1379 err = crypto_shash_update(&desc.shash, address, length); 1380 BUG_ON(err); 1381 1382 return *(u32 *)desc.ctx; 1383} 1384 1385/* Return most recent uncommitted transaction */ 1386static inline tid_t jbd2_get_latest_transaction(journal_t *journal) 1387{ 1388 tid_t tid; 1389 1390 read_lock(&journal->j_state_lock); 1391 tid = journal->j_commit_request; 1392 if (journal->j_running_transaction) 1393 tid = journal->j_running_transaction->t_tid; 1394 read_unlock(&journal->j_state_lock); 1395 return tid; 1396} 1397 1398#ifdef __KERNEL__ 1399 1400#define buffer_trace_init(bh) do {} while (0) 1401#define print_buffer_fields(bh) do {} while (0) 1402#define print_buffer_trace(bh) do {} while (0) 1403#define BUFFER_TRACE(bh, info) do {} while (0) 1404#define BUFFER_TRACE2(bh, bh2, info) do {} while (0) 1405#define JBUFFER_TRACE(jh, info) do {} while (0) 1406 1407#endif /* __KERNEL__ */ 1408 1409#endif /* _LINUX_JBD2_H */ 1410